Mill



Nov. 6, 1928. 1,690,496

F. E. MARCY MILL Filed March 21, 1928 INVENTOR Patented Nov. 6, 1928.

UNITED 4STATES Pa/TENT OFFICE.

rmx E. manor, or SAN mao, cauronms.

original applications led June 7, 1927, serial `No. 197,054, and December 28 1927, s erlal No. 248,058.

Divided and this application led March 21, 1928. Serial No. 268,408.

This invention relates to an improvement in mills employing a rotary drum or barrel in which the material to be reduced and the necessary reducing medium such as bars,

5 pebbles, cubes, rods, etc. are confined, the material being crushed or reduced by impact and attrition as the mill load tumbles and cascades during the rotation of the mill drum.

One of the objects of my invention is to provide a'mill structure in which the efficiency of the mill is materially increased, this object being accomplished in part by providing a structure for freeing the mill grate of oversize and reducin medium thereby preventing l5 pluggingv or locking of the grate openings and permitting of the escape of the fines therethrough. f While in the mills of the type to which this invention is directed there is a constant migration of the mill load toward the discharge end of the mill drum due to the head provided by the continuous feeding of material to the feed end of the mill drum and the discharge of this material from. the vdischarge end, the

u mill of the present invention is provided with means for increasing this migrating action, the grate, however,'as above mentioned being maintained free of oversize and reducing medium so as to permit of the lines which are traveling forward with the migrating -load to find their way readily through the grates to the outside of the mill.

In the drawings, Fig. 1 shows an embodiment ofmy invention in sectional elevation,

the section'being taken substantiallyon the line 1-1` of Fig. 2; i

Fig. 2 is a sectionl taken through the construction of Fig. 1 looking toward the dis charge end of the mill.

Referring to the drawings in detail, 1 designates the rotary drum or barrel of the mill. This drum, as will be understood by those skilled in this artis provided with a feed head 2 and feed trunnion 3 and with a dis- 5 charge head 4 and discharge trunnion 5. The trunnions 3 and 5 asis usual are mounted in suitable bearings. As this construction is conventional the same has not been illustrated. The interior of the drum 1 is provided with stepped liners 6, these liners being so constructed and arranged as to provide liners sloping toward the discharge head 4 on the ascending or rising side of the drum '1, thereby to effect an increase in the migrating action of the mill load toward the discharge end as the drum is rotated. The mill is assumed to be rotating toward the observer as viewed in Fig. 1.

Adjacent the discharge head 4 I provide a plurality of grate sectors7 disposed transversely of the mill drum. The grate inwardly of the mill beyond theplane of the inner face of the grate sectors.

`The grate sectors 7 and grate-retaining sectors 9 are 'assembled about a central' sub-A stantially conical member Iand/are set at a shght incline so thatthe entire structure composed of the grate sectors 7 grateretaining sectors 9 and conical member 10 provide aA substantially conical wall across the mill o nings 8 in the sectors extend transversely o thev mill drum. Intermediate adjacent grate secdrum, the base of the cone facing outwardly of the mill toward the, discharge end.

In the o ration of this mill the migration i of the mil load. toward the discharge end is vaccelerated by the provision of the sloping liners 6, as above described,` sloping toward the ate and the discharge en d of the mill on tig ascending or rising side of the `mill drum, causing t e mill load to work toward the feed endj at an increased speed. The

fines traveling with the mill load will escape through the transversely extending grate openings 8 in the grate sectors 7 and to prevent these openings from becoming plu ged or blocked by oversize and to preventI bloc g of these grate openings by the reducing medium the imperforate grate sectors 9 have been provided, these members operating to carry the oversize and reducing medium upwardly as the drum is rotated, the overslze and reducing medium then falling upon the face of the conical shaped member 10 to be worked toward the feed end of the mill, 1. e., 1n a direct-ion away from the grate sectors. The net result of this construction is that the grate sectors will be maintained relatively free of oversize and reducing medium at all times so as to permit of the ready escape of the lines llllxjrnough the grate openings and out of the This application is a division of my co- 'prending application Serial No. 197,054, filed grate sectors and solid sectors are assembled,

Said solid sectors and said conical member cooperating with the grate sectors'to free the grate of oversize.

2. A mill comprising in combination, a rotary drum or barrel, grate sectors and solid sectors alternating disposed adjacent the discharge end .of the drum, said grate sectors and solid sectors together providing a substantially conical structure extending transversey of the mill drum.

mill comprising in combination, a

rotary drum or barrel, grate sectors having grate openin s extendingtransversely of the mill drum a jacent the dlscharge end of the mill drum, and imperforate sectors interi mediate the grate sectors, said imperforate sectors lcooperating with the grate sectors for `freeing the latter if oversize.

-' 4. A mill comprising in combination, a

rotary drum or barreLgrate sectors disposed across the drum adjacent the discharge end thereof, and grate-retaining imperforate sec tors intermediate the grate sectors.

5. A mill comprising in combination, a

rotary drum or barrel, grate openings extending transversely of the drum disposed adjacent the discharge end oi the drum, and `imperforate grate-retaining se'ctors intermediate adjacent grate sectors, the inner face of said grate-retaining sectors extending inwardly of the mill beyond the plane of the grate sectors.- i

6. A mill comprising in rotary drum or barrel, grate sectors and 1mperforate grate-retaining sectors alternatin disposed adjacent the discharge end of the sai drum, and aconical member about which the said grate sectors and grate-retaining sectors areV assembled.

7. A mill comprising in combination, a rotary drum or barrel, grate sectors and imperforate grate-retaining sectors alternating disposed adjacent the discharge end of said drum transversely thereof, a central conical member about which the grate sectors and the grate-retaining sectors are assembled, said grate sectors, grate-retaining sectors and the central conical member being so disposed as to provide a substantially conical structure adjacent the discharge end of the mill.

This y specification signed this 15 day of March, 1928.` Y 7' FRANK E. MRCY.

combination, a

grate sectors having 

